Hoist clamp



Nov.. 1, 1960 K. L.. clANcHETTE HOIST CLAMP 2 Sheets-Sheet l Filed Sept. 22, 1958 Maw, l, 1960 K. 1 cxANcHETTE 2,958,557

HoIsT CLAMP Filed Sept. 22, 1958 2 Sheets-S1188?. 2

-vzr ma United States Patent HOIST CLAMP Kenneth L. Cianchette, Pittsfield, Maine, assignor to Ken ganchette, Inc., Pittslield, Maine, a corporation of arne Filed Sept. 22, 1958, Ser. No. 762,501

4 Claims. (Cl. 294-106) This invention relates to hoists for use in steel erection, and more particularly to clamping devices for securing a structural beam to the hoist cable so that the beam can be lifted.

According to conventional practice in handling structural steel beams a sling cable with eyes at both ends is placed around the beam, and the eyes are engaged by a hook on the hoist cable. Ihis arrangement is not entirely safe or satisfactory because the beam can sway and tilt, or even slide out endwise if not carefully balanced in the sling. Furthermore, it is often diicult to get the sling under a beam which is lying on the ground or on a pile of other beams. It is often necessary to jack the beam up in order to put the sling in position.

The object of this invention is to provide a clamping device which can be used in connection with a standard hook hoist, which will securely grip a beam so that it can be lifted by the hoist, which prevents the beam from sliding or tilting, which is adapted for lifting beams of a variety of standard structural shapes and sizes, which can be readily engaged with a beam which is lying on the ground, and which is simple in construction, durable and inexpensive. Other advantages and novel features of the device will be apparent from the following description.

In the drawings illustrating the invention:

Fig. 1 is a vertical cross-section, taken along line 1 1 ofFig. 2, showing the clamping device in place on a beam;

Fig. Z is a side elevation of the device; and

Fig. 3 is a vertical cross-section showing the device being lowered on to a beam.

The clamp has a frame or yoke generally indicated by the numeral 10, made of steel for example, and consisting of two upstanding brackets 11 and 12 connected at the bottom by a bridging portion 13. The brackets, which may be cast or welded together, consist of webs 9 and 14, inner anges 15 and 16, outer anges 17 and 18, and bottom flanges 19 and 20, the bottom surfaces of which are lush with the bottom surfaces of bridging portion 13, the aforesaid arrangement being such that said bottom flanges together form the frame base part or member. The inner flanges 15 and 16 are spaced apart so that the frame has a central slot 21, and carry pairs of guides 22 and 23, respectively.

An inverted U-shaped link 24 is mounted to slide between guides 22 and 23, and is secured to a shackle 25 by means of a pin 26. The shackle is adapted to be engaged by the hook 27 on a hoist cable 28 of a standard type of hoist, such as a crane.

Link 24 carries a pin 30 on which are rotatably mounted a centrally disposed link 31 and a pair of links 32 and 33, all of similar construction. A xed pin 34 is mounted in anges 15 and 16. A first pair of parallel links 35 and 36, and a second pair of parallel links 37 and 38, are rotatably mounted at their lower ends on pin 34, and are maintained in the proper axial ice position on the pin by spacer blocks 39, 40 and 41. Links 35 and 36 are rotatably secured to the lower ends of links 32 and 33 by a pin 42. A washer 43 maintains the lower ends of links 32 and 33 in parallel relationship. Links 37 and 38 are rotatably connected to the lower end of link 31 by means of a pin 44.

A pair of similar but oppositely disposed hook arms 45 and 46 are carried by the parallel linkage just described. These arms are made of generally channelshaped section with forked upper portions consisting of legs 45a, 45h, and 46a, 46b (not shown), respectively. Leg 45a is rotatably connected to link 35 by a pin 47, and leg 45b is rotatably connected to link 36 by a pin 48, said pins being located at corresponding points of said links which are disposed above the points of connection of said links by the fixed pin 34. Legs 46a and 46b are rotatably secured to links 37 and 38 by a pin 49. Suitable spacing washers 50, only the central one of which is here visible, maintain the legs 46a and 46b in the proper axial position on pin 49 so that arm 46 is in line with arm 45, as viewed in Fig. 2.

Arms 45 and 46 have hook portions 45C and 46c, respectively, on their lower ends. These portions have convexly curved upper edges 45d and 46d and lower edges 45e and 46e.

The clamp is intended to be used on structural steel beams which have la web and at least one flange, such as I-beams, H-beams, or T-beams. In the drawing the upper part of an I-beam 60, having a web 60a and opposed top ange portions 60b, is shown by way of example. When the clamp is empty and is lifted by the shackle 25, link 24 slides up with respect to the frame, and the parallel linkage consisting of links 31, 32, 33, 35, 36, 37 and 38, elongates in the vertical direction, assuming the position shown in Fig. 3, with hook arms 45 and 46 swinging freely. When the clamp is lowered on to the beam to be picked up, the curved lower edges 45e, 46e of the hooked arms engage the top ilange 60h and cause the hook arms to swing outward. As soon as the frame 10 cornes to rest on the top flange 6017, further lowering of link 24 will allow the parallel linkage to expand sideways. Arms 45 and 46 continue to swing outward until the inner ends of the hook portions 45e and 46c clear the edges of the ange. The link 24 is lowered until arms 45 and 46 vdrop down and swing inward with edges 45d and 46d engaged with the under side of the flange. When these arms and the parallel linkage are in the position shown in Fig. 1, the clamp is in position for hoisting.

Once hook portions 45C and 46c are engaged under the top flange of the beam, it is apparent that any lifting force applied to link 24 will tend to swing the pairs of links 35, 36 and 37, 3S inward toward each other and thus apply an inward and upward force to arms 45 and 46 which causes said hook portions to move into tight gripping engagement with the under faces of the beam flanges 60h. In addition, said hook arms 45, 46 exert downward pull on said links 35, 36 and 37, 38 which causes same to impart downward thrust on the bridging portion 113 `and bottom flanges 19, 20 of the frame member against the beam anges 60b. The fianges 60h will thus be clamped in the sidewise direction between the hook arms 45, 46 and in the vertical direction between hook portions 45C, 46c and the bottom of frame 10. The clamping force will be directly proportionate to the weight of the beam when the beam is lifted by the hoist.

The clamp will always seat itself squarely on the beam because the bottom of the frame 10 is flat and extends over a substantial area. It will be noted in Fig. 2 that the frame extends arr appreciable distance in the longitudinal .direction of tlhe beam to either side of the parallel linkage. The beam is thus prevented from tilting in the clamp. The positive grip provided by the bottom of the frame and the hook arms also prevents the beam from sliding longitudinally through the clamp, as is likely to occur when a sling is used. It is another feature of the invention that the aforesaid parallel linkage means as a whole is maintained perpendicular to the beam top anges 60h under lifting forces which would otherwise tend to cock and possibly distort said linkage means consequent to said means operating in the confined space between the bracket flanges 15, 16 and/or the guides 22, 23 carried thereby.

When the beam has been moved to the desired position, the clamp can be readily disengaged by lowering shackle 25 until the force on the parallel linkage is relieved. Hook arms l45 and 46 can then be pushed out and disengaged from the top ilange.

The clamp may be made in various sizes, but a single size will handle a wide range of beam sizes, because the parallel linkage will lock in various positions according to the width of the beam flange. The minimum and maximum widths of flanges which can be accommodated depend mainly on the dimensions of the arms 45, 46 and their hook portions.

The device here disclosed can be applied to a beam which is lying on the ground, and can be readily engaged and disengaged by one man. Furthermore, the beam is more easily controlled when carried by this device instead of the customary sling, and is not likely to slip. This device, accordingiy, makes the handling of structural beams muc/h easier and safer, as well as eliminating much of the laber formerly required.

What is claimed is:

1. A hoist clamp for structural beams of the type having opposed top flanges comprising a base member adapted to be lowered flat on to said top flanges and carrying a xed pin, vertically elongatable land sidewardly spreadable linkage means connected at its bottom end to said Xed pin and mounting a hoisting-hook engaging shackle at its upper end, said linkage means including a pair of lower link arms connected together at their lower ends by said xed pin and being swingable towards and away from one another in a plane extending transversely of the base member, a pair of similar but oppositely disposed hooks pivotally connected at their upper ends to said link arms at corresponding points therealong disposed above the fixed pin, said hooks hanging freely from said link arms and having length such tlhat their working ends are adapted to eng-age beneath said top flanges when said linkage means is eX- tended sidewardly, the construction and arrangement being such that, when the clamp is lowered on to the top anges of the beam, the linkage means is spread sidewardly under its own weight and the working ends of the hook will move outwardly over and thence under said top anges, and that when hoisting begins the linkage means tends to elongate whereupon the hooks, in addition to gripping to the under faces of said top flanges, exert downward pull on said lower link arms causing same to impart downward thrust on the base member against the beam top flange.

2. A hoist clamp as defined in claim 1, wherein said base member has substantial length dimension longitudinally of the beam and said pin is mounted in its middle length portion, thereby to prevent relative tilting of clamp with respect to beam.

3. A vhoist clamp as dened in claim 1, wherein said base member has substantial length dimension longitudinally of the beam and said Xed pin is mounted to the middle length portion thereof, and said base member is further provided with means extending normally therefrom in a plane intersected by the linkage means for maintaining said linkage means perpendicular to the beam top anges during hoisting.

4. A hoist clamp as defined in claim 3, wherein said means for maintaining the linkage means perpendicular to the beam top flanges comprises a pair of brackets spaced from one another a distance closely corresponding to the thickness dimension of said linkage means.

References Cited in the le of this patent UNITED STATES PATENTS 

